"A Yo-kai that has been united with the engine room of the demonic express. Because of the continuation of the driver for a long time, he himself drives an express by eating coal, but if he eats too much, it gets hot and angry easily, and the runaway continues, everywhere ...!"
Boso Mister Mattana is a large Yo-kai whose body is mostly compossed by his head, gray in color, with the mouth area colored red; sporting four large fangs inside the mouth. He has three eyes: a green eye in his front, and two uneven eyes resembling pressure meters, the left one being larger and more detailed -with scale-like markings rounding it-. He has comparatively shorter and smaller arms with gloved hands. He sports a driver's hat, alluding to his position in the Youma Train.
Boso Mister Mattana appears to have a very short temper.
He has enough energy to keep the Youma Train running, being connected to the engine system.
In this boss battle, each blow Boso Mister Mattana receives fills a two-fold red bar in the left side of the background and a blue bar in the right side of the background. Pinning the valves in said side causes each of the bars to fill faster.
Boso Mister Mattana appears at the engine room of the Youma Train.
""Boso" describes the following: "running wildly; reckless driving; runaway; rampage".